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<head><meta charset="utf-8"><title>weekly meeting 2018-12-17 · wg-traits · Zulip Chat Archive</title></head>
<h2>Stream: <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/index.html">wg-traits</a></h2>
<h3>Topic: <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-12-17.html">weekly meeting 2018-12-17</a></h3>

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<a name="152049083"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-12-17/near/152049083" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> scalexm <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-12-17.html#152049083">(Dec 17 2018 at 18:26)</a>:</h4>
<p><span class="user-mention" data-user-id="116009">@nikomatsakis</span> is there a meeting this evening?</p>



<a name="152051718"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-12-17/near/152051718" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-12-17.html#152051718">(Dec 17 2018 at 19:02)</a>:</h4>
<p><span class="user-mention" data-user-id="131694">@scalexm</span> I was just coming :)</p>



<a name="152051732"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-12-17/near/152051732" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-12-17.html#152051732">(Dec 17 2018 at 19:03)</a>:</h4>
<p>cc <span class="user-group-mention" data-user-group-id="692">@WG-compiler-traits</span> -- brief meeting?</p>



<a name="152051742"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-12-17/near/152051742" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-12-17.html#152051742">(Dec 17 2018 at 19:03)</a>:</h4>
<p><span class="user-mention" data-user-id="131694">@scalexm</span> I've been reading your PR (at long last!)</p>



<a name="152051745"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-12-17/near/152051745" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Alexander Regueiro <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-12-17.html#152051745">(Dec 17 2018 at 19:03)</a>:</h4>
<p>sure</p>



<a name="152051754"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-12-17/near/152051754" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-12-17.html#152051754">(Dec 17 2018 at 19:03)</a>:</h4>
<p>I was hoping, if people are around, to talk a bit briefly about the next year</p>



<a name="152051755"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-12-17/near/152051755" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Alexander Regueiro <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-12-17.html#152051755">(Dec 17 2018 at 19:03)</a>:</h4>
<p>not sure I can contribute much right now though</p>



<a name="152051759"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-12-17/near/152051759" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-12-17.html#152051759">(Dec 17 2018 at 19:03)</a>:</h4>
<p>(I imagine we won't have a meeting next week)</p>



<a name="152051761"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-12-17/near/152051761" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Alexander Regueiro <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-12-17.html#152051761">(Dec 17 2018 at 19:03)</a>:</h4>
<p>yeah</p>



<a name="152051764"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-12-17/near/152051764" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Alexander Regueiro <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-12-17.html#152051764">(Dec 17 2018 at 19:03)</a>:</h4>
<p>Chrismtas Eve and all</p>



<a name="152051826"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-12-17/near/152051826" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-12-17.html#152051826">(Dec 17 2018 at 19:04)</a>:</h4>
<p>but I'm hoping that starting in January 2019 I can start to devote more dedicated time to traits etc. I'm not sure what that should mean yet</p>



<a name="152051829"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-12-17/near/152051829" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Alexander Regueiro <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-12-17.html#152051829">(Dec 17 2018 at 19:04)</a>:</h4>
<p>nice</p>



<a name="152051834"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-12-17/near/152051834" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Alexander Regueiro <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-12-17.html#152051834">(Dec 17 2018 at 19:04)</a>:</h4>
<p>upcasting and multi-traits! :-D</p>



<a name="152051843"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-12-17/near/152051843" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Alexander Regueiro <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-12-17.html#152051843">(Dec 17 2018 at 19:04)</a>:</h4>
<p>I pinged you in the channel where @dhardy and I were talking about it.</p>



<a name="152051846"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-12-17/near/152051846" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-12-17.html#152051846">(Dec 17 2018 at 19:04)</a>:</h4>
<p>I saw that, haven't had time to follow up yet</p>



<a name="152051869"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-12-17/near/152051869" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-12-17.html#152051869">(Dec 17 2018 at 19:05)</a>:</h4>
<p>I'm not sure what exactly to discuss, I guess it's a lot of the same questions as ever</p>



<a name="152051875"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-12-17/near/152051875" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Alexander Regueiro <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-12-17.html#152051875">(Dec 17 2018 at 19:05)</a>:</h4>
<p>no worries. in your own time</p>



<a name="152051876"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-12-17/near/152051876" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-12-17.html#152051876">(Dec 17 2018 at 19:05)</a>:</h4>
<p>but actually having I think a kind of list of "goals" would be a good 1st step</p>



<a name="152051884"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-12-17/near/152051884" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Alexander Regueiro <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-12-17.html#152051884">(Dec 17 2018 at 19:05)</a>:</h4>
<p>yes, it's the same questions as before... although @dhardy had some more specific ones I think, which I couldn't answer.</p>



<a name="152051933"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-12-17/near/152051933" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-12-17.html#152051933">(Dec 17 2018 at 19:06)</a>:</h4>
<p>I wonder if it makes sense to create a repository (or perhaps use some part of <a href="https://github.com/rust-lang/compiler-team/" target="_blank" title="https://github.com/rust-lang/compiler-team/">https://github.com/rust-lang/compiler-team/</a>) to track this sort of thing</p>



<a name="152051937"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-12-17/near/152051937" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> tmandry <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-12-17.html#152051937">(Dec 17 2018 at 19:06)</a>:</h4>
<p>since I've been out of the loop for a bit.. what's the status on chalkification?</p>



<a name="152051956"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-12-17/near/152051956" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Alexander Regueiro <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-12-17.html#152051956">(Dec 17 2018 at 19:06)</a>:</h4>
<p>I'm not hugely fond of the rfc-repo idea but... would some notes, then a pre-RFC or such work?</p>



<a name="152051964"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-12-17/near/152051964" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-12-17.html#152051964">(Dec 17 2018 at 19:06)</a>:</h4>
<p>the status is that <span class="user-mention" data-user-id="131694">@scalexm</span> has opened <a href="https://github.com/rust-lang/rust/issues/56384" target="_blank" title="https://github.com/rust-lang/rust/issues/56384">#56384</a> but I've been slow to review</p>



<a name="152051965"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-12-17/near/152051965" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Alexander Regueiro <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-12-17.html#152051965">(Dec 17 2018 at 19:06)</a>:</h4>
<p>after which an RFC can come finally</p>



<a name="152052008"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-12-17/near/152052008" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Alexander Regueiro <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-12-17.html#152052008">(Dec 17 2018 at 19:07)</a>:</h4>
<p><span class="user-mention" data-user-id="116009">@nikomatsakis</span> would appreciate some advice on what to do about that future compat warning for my trait aliases PR btw... I think that should become a regular lint, but we should leave a future compat warning in place for the coherence case? I'm not sure how to do it for coherence though, sounds kind of difficult.</p>



<a name="152052011"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-12-17/near/152052011" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-12-17.html#152052011">(Dec 17 2018 at 19:07)</a>:</h4>
<p>if there were to be a repository, I was thinking more of a higher-level one, just collecting all the things that the working group is trying to do</p>



<a name="152052015"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-12-17/near/152052015" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Alexander Regueiro <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-12-17.html#152052015">(Dec 17 2018 at 19:07)</a>:</h4>
<p>fiar enough</p>



<a name="152052121"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-12-17/near/152052121" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-12-17.html#152052121">(Dec 17 2018 at 19:09)</a>:</h4>
<blockquote>
<p><span class="user-mention" data-user-id="116009">@nikomatsakis</span> would appreciate some advice on what to do about that future compat warning for my trait aliases PR btw... I think that should become a regular lint, but we should leave a future compat warning in place for the coherence case? I'm not sure how to do it for coherence though, sounds kind of difficult.</p>
</blockquote>
<p>ok ye I can do that today</p>



<a name="152052123"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-12-17/near/152052123" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> tmandry <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-12-17.html#152052123">(Dec 17 2018 at 19:09)</a>:</h4>
<p>that could work</p>



<a name="152052218"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-12-17/near/152052218" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-12-17.html#152052218">(Dec 17 2018 at 19:10)</a>:</h4>
<p>one of the things I'm thinking about</p>



<a name="152052225"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-12-17/near/152052225" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-12-17.html#152052225">(Dec 17 2018 at 19:10)</a>:</h4>
<p>is trying to do a kind of survey</p>



<a name="152052228"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-12-17/near/152052228" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> tmandry <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-12-17.html#152052228">(Dec 17 2018 at 19:10)</a>:</h4>
<p>it begs the question, where should tracking issues live? rust repo vs here?</p>



<a name="152052255"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-12-17/near/152052255" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-12-17.html#152052255">(Dec 17 2018 at 19:11)</a>:</h4>
<p>basically I'm wondering about which features are most important and for what, and if -- for those -- there exist shortcuts to implementing them. I really want to push on chalk integration but I am wary that it may take some time before it's all competitive and full-featured</p>



<a name="152052265"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-12-17/near/152052265" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-12-17.html#152052265">(Dec 17 2018 at 19:11)</a>:</h4>
<p>so I guess I'm just thinking about trying to get a "high-level feeling" for the scope of the goals and try to organize them somewhat</p>



<a name="152052274"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-12-17/near/152052274" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-12-17.html#152052274">(Dec 17 2018 at 19:11)</a>:</h4>
<p>(e.g., withoutboats was asking me about <code>async fn</code> in traits recently)</p>



<a name="152052355"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-12-17/near/152052355" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> centril <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-12-17.html#152052355">(Dec 17 2018 at 19:12)</a>:</h4>
<p><span class="user-mention" data-user-id="116009">@nikomatsakis</span>  GATs are the most important thing ever of course <span class="emoji emoji-1f642" title="slight smile">:slight_smile:</span> (by several orders of magnitude...) ^.^</p>



<a name="152052358"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-12-17/near/152052358" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> scalexm <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-12-17.html#152052358">(Dec 17 2018 at 19:12)</a>:</h4>
<p>well</p>



<a name="152052364"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-12-17/near/152052364" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-12-17.html#152052364">(Dec 17 2018 at 19:12)</a>:</h4>
<p><span class="user-mention" data-user-id="126931">@centril</span> that is not clear to me</p>



<a name="152052377"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-12-17/near/152052377" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> scalexm <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-12-17.html#152052377">(Dec 17 2018 at 19:12)</a>:</h4>
<p>I don't know a lot of trait-related features that are blocked on chalk apart from GATs basically</p>



<a name="152052380"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-12-17/near/152052380" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> tmandry <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-12-17.html#152052380">(Dec 17 2018 at 19:12)</a>:</h4>
<p>I think those would have to be prioritized pretty ruthlessly by opportunity cost of working on chalk vs immediate benefit</p>



<a name="152052381"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-12-17/near/152052381" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-12-17.html#152052381">(Dec 17 2018 at 19:12)</a>:</h4>
<p>(but maybe so)</p>



<a name="152052420"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-12-17/near/152052420" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> centril <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-12-17.html#152052420">(Dec 17 2018 at 19:13)</a>:</h4>
<p><span class="user-mention" data-user-id="116009">@nikomatsakis</span>  well; at least personally, GATs are consistently the <a href="https://github.com/rust-lang/rust/issues/1" target="_blank" title="https://github.com/rust-lang/rust/issues/1">#1</a> thing that I frequently need that makes me go "nope, just give up... can't make progress"</p>



<a name="152052466"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-12-17/near/152052466" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> tmandry <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-12-17.html#152052466">(Dec 17 2018 at 19:14)</a>:</h4>
<p>async fn in traits is just existential types?</p>



<a name="152052474"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-12-17/near/152052474" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-12-17.html#152052474">(Dec 17 2018 at 19:14)</a>:</h4>
<p><span class="user-mention" data-user-id="131694">@scalexm</span> lazy norm, perhaps, and implied bounds — but maybe not. I guess that's part of the question.</p>



<a name="152052486"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-12-17/near/152052486" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> scalexm <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-12-17.html#152052486">(Dec 17 2018 at 19:14)</a>:</h4>
<p><span class="user-mention" data-user-id="116883">@tmandry</span> yes but they often need to be generic over a lifetime (for a method taking <code>&amp;self</code> for example)</p>



<a name="152052500"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-12-17/near/152052500" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-12-17.html#152052500">(Dec 17 2018 at 19:15)</a>:</h4>
<blockquote>
<p>async fn in traits is just existential types?</p>
</blockquote>
<p>it depends on how "purely" you want to do it. It would be best modeled with GATs and some existential support, but we might be able to do a more "focused" version</p>



<a name="152052512"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-12-17/near/152052512" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-12-17.html#152052512">(Dec 17 2018 at 19:15)</a>:</h4>
<p>special-cased</p>



<a name="152052515"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-12-17/near/152052515" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-12-17.html#152052515">(Dec 17 2018 at 19:15)</a>:</h4>
<p>but that is what I am bit wary of</p>



<a name="152052534"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-12-17/near/152052534" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-12-17.html#152052534">(Dec 17 2018 at 19:15)</a>:</h4>
<p>the other "feature" of traits is perhaps "performance", which I still <em>feel</em> can be vastly improved via the more aggressive caching that chalk permits etc, but I think that may take some time to prove out (and could be wrong)</p>



<a name="152052581"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-12-17/near/152052581" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-12-17.html#152052581">(Dec 17 2018 at 19:16)</a>:</h4>
<p><span class="user-mention" data-user-id="126931">@centril</span> yes, fair. Mostly I am wondering if some kind of <code>async fn</code> implementation might be as important.</p>



<a name="152052598"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-12-17/near/152052598" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-12-17.html#152052598">(Dec 17 2018 at 19:16)</a>:</h4>
<p>ps, <span class="user-mention" data-user-id="131694">@scalexm</span> I'd like to try and land your PR before the holidays, are you available to rebase etc these days?</p>



<a name="152052600"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-12-17/near/152052600" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-12-17.html#152052600">(Dec 17 2018 at 19:16)</a>:</h4>
<p>I see you recently rebased it</p>



<a name="152052604"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-12-17/near/152052604" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-12-17.html#152052604">(Dec 17 2018 at 19:16)</a>:</h4>
<p>(I can also do that if needed)</p>



<a name="152052605"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-12-17/near/152052605" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> tmandry <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-12-17.html#152052605">(Dec 17 2018 at 19:16)</a>:</h4>
<p>my feeling is it's hard to have a nuanced conversation about this without an idea of what such a special-cased version would look like..</p>



<a name="152052610"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-12-17/near/152052610" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-12-17.html#152052610">(Dec 17 2018 at 19:16)</a>:</h4>
<p>yes I don't really want to have that conversation now</p>



<a name="152052614"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-12-17/near/152052614" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> scalexm <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-12-17.html#152052614">(Dec 17 2018 at 19:16)</a>:</h4>
<p><span class="user-mention" data-user-id="116009">@nikomatsakis</span>  I should be available in the evenings (my time) yes</p>



<a name="152052626"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-12-17/near/152052626" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-12-17.html#152052626">(Dec 17 2018 at 19:16)</a>:</h4>
<p>I mostly wanted to get an idae of the "end user things" we want to enable and try to take some time to think about what's really the best path for each of them</p>



<a name="152052659"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-12-17/near/152052659" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> centril <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-12-17.html#152052659">(Dec 17 2018 at 19:17)</a>:</h4>
<p><span class="user-mention" data-user-id="116009">@nikomatsakis</span>  I mean; for many people async fn is really important; but it's less a general type system feature which pervasively makes everything better and more a focused domain specific thing</p>



<a name="152052761"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-12-17/near/152052761" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> centril <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-12-17.html#152052761">(Dec 17 2018 at 19:18)</a>:</h4>
<p>besides, async fn semi-depending on GATs is a reason to focus on GATs...</p>
<p>re. performance... isn't most time spent in code-gen anyways?</p>



<a name="152052765"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-12-17/near/152052765" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-12-17.html#152052765">(Dec 17 2018 at 19:18)</a>:</h4>
<p>I wonder if it makes sense to literally do some sort of survey</p>



<a name="152052789"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-12-17/near/152052789" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> tmandry <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-12-17.html#152052789">(Dec 17 2018 at 19:19)</a>:</h4>
<p>so, do we want to prioritize shipping a really polished async feature, or letting things take their course and ending up more good things in the end, a little sooner</p>



<a name="152052796"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-12-17/near/152052796" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-12-17.html#152052796">(Dec 17 2018 at 19:19)</a>:</h4>
<p>or perhaps an internals thread makes more sense. I guess the real question is what the questions are</p>



<a name="152052800"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-12-17/near/152052800" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-12-17.html#152052800">(Dec 17 2018 at 19:19)</a>:</h4>
<p>maybe neither</p>



<a name="152052896"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-12-17/near/152052896" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-12-17.html#152052896">(Dec 17 2018 at 19:21)</a>:</h4>
<p><span class="user-mention" data-user-id="126931">@centril</span> re: performance, it all depends what you're doing, but trait matching can be a significant cost in many scenarios. Some of my measurements put it at about 30% of e.g. serde build time, though I think those measurements are a touch suspect because of incomplete debuginfo</p>



<a name="152053011"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-12-17/near/152053011" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-12-17.html#152053011">(Dec 17 2018 at 19:22)</a>:</h4>
<p>but certainly <code>cargo check</code> is not spending time in LLVM =)</p>



<a name="152053028"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-12-17/near/152053028" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> centril <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-12-17.html#152053028">(Dec 17 2018 at 19:22)</a>:</h4>
<p>sure; check is usually pretty fast tho imo :P</p>



<a name="152053034"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-12-17/near/152053034" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> tmandry <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-12-17.html#152053034">(Dec 17 2018 at 19:22)</a>:</h4>
<p>based on my wording above, my feeling is this boils down to a higher-level strategic question that could use guidance from core team or more general rust community</p>



<a name="152053049"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-12-17/near/152053049" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-12-17.html#152053049">(Dec 17 2018 at 19:22)</a>:</h4>
<p>I'm wondering</p>



<a name="152053053"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-12-17/near/152053053" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-12-17.html#152053053">(Dec 17 2018 at 19:22)</a>:</h4>
<p>I think it's a combination</p>



<a name="152053068"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-12-17/near/152053068" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> centril <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-12-17.html#152053068">(Dec 17 2018 at 19:23)</a>:</h4>
<p><span class="user-mention" data-user-id="116009">@nikomatsakis</span>  what does async fn need implied bounds for?</p>



<a name="152053089"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-12-17/near/152053089" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-12-17.html#152053089">(Dec 17 2018 at 19:23)</a>:</h4>
<p>like, the technical details matter, I don't think we are under such heavy time pressure on any thing that we want to take on a lot of technical debt necessarily</p>



<a name="152053100"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-12-17/near/152053100" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> tmandry <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-12-17.html#152053100">(Dec 17 2018 at 19:23)</a>:</h4>
<p>right</p>



<a name="152053172"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-12-17/near/152053172" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-12-17.html#152053172">(Dec 17 2018 at 19:24)</a>:</h4>
<p>so I am guessing that the place to start is this:</p>
<ul>
<li>try to map out a list of all the things that I can come up of "needs people have"</li>
<li>open an internals thread looking for feedback on stuff that got overlooked</li>
</ul>
<p>I think e.g. the trait object + alias stuff that <span class="user-mention" data-user-id="124069">@Alexander Regueiro</span> has been pursuing is really great, and not something that was originally on my radar</p>



<a name="152053188"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-12-17/near/152053188" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-12-17.html#152053188">(Dec 17 2018 at 19:24)</a>:</h4>
<blockquote>
<p>what does async fn need implied bounds for?</p>
</blockquote>
<p>there's no particular connection</p>



<a name="152053198"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-12-17/near/152053198" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-12-17.html#152053198">(Dec 17 2018 at 19:24)</a>:</h4>
<p>it's just that implied bounds need chalk</p>



<a name="152053204"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-12-17/near/152053204" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-12-17.html#152053204">(Dec 17 2018 at 19:25)</a>:</h4>
<p>but omg they would be so nice sometimes ;)</p>



<a name="152053217"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-12-17/near/152053217" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-12-17.html#152053217">(Dec 17 2018 at 19:25)</a>:</h4>
<p>/me has gotten sick of copying and pasting where clauses all over the place</p>



<a name="152053257"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-12-17/near/152053257" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> tmandry <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-12-17.html#152053257">(Dec 17 2018 at 19:25)</a>:</h4>
<p>I think there is also a lot of value in finishing things and sometimes that needs to be a priority</p>



<a name="152053317"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-12-17/near/152053317" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> tmandry <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-12-17.html#152053317">(Dec 17 2018 at 19:26)</a>:</h4>
<p>so we should definitely keep that in mind imo</p>



<a name="152053374"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-12-17/near/152053374" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-12-17.html#152053374">(Dec 17 2018 at 19:27)</a>:</h4>
<p>so let's see, what is the list? here is a hackmd document with some preliminary thoughts: <a href="https://hackmd.io/i32CFrbQSsmDZ0vBheggWg" target="_blank" title="https://hackmd.io/i32CFrbQSsmDZ0vBheggWg">link</a></p>



<a name="152053382"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-12-17/near/152053382" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> centril <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-12-17.html#152053382">(Dec 17 2018 at 19:27)</a>:</h4>
<p>OK; I'll say a few things: 1) I'm not inclined to stabilize trait aliases until we at least have ConstraintKinds on nightly for some time (and it hasn't even been designed / rfc-accepted); 2) same with implied bounds but instead with <code>where</code> bounds on enum variants since implied bounds makes all APIs not able to move to more relaxed constraints (it's a breaking change); 3) specialization needs redesign;</p>



<a name="152053466"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-12-17/near/152053466" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-12-17.html#152053466">(Dec 17 2018 at 19:28)</a>:</h4>
<p>actually, just making that list and trying to sketch out what is needed for each category is pretyy interesting</p>



<a name="152053498"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-12-17/near/152053498" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> tmandry <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-12-17.html#152053498">(Dec 17 2018 at 19:29)</a>:</h4>
<p>also, <em>I suspect</em> finishing chalkification should make it easier to iterate on a lot of things we're talking about</p>



<a name="152053534"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-12-17/near/152053534" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> tmandry <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-12-17.html#152053534">(Dec 17 2018 at 19:29)</a>:</h4>
<p>but I may be misguided there</p>



<a name="152053628"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-12-17/near/152053628" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> centril <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-12-17.html#152053628">(Dec 17 2018 at 19:30)</a>:</h4>
<p>yeah; <span class="user-mention" data-user-id="116883">@tmandry</span>  I'm working on an RFC for <code>for&lt;T: Foo + 'a&gt;</code> +/- generic closures; that would also benefit from chalk</p>



<a name="152053632"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-12-17/near/152053632" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> scalexm <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-12-17.html#152053632">(Dec 17 2018 at 19:30)</a>:</h4>
<p><span class="user-mention" data-user-id="126931">@centril</span> could you elaborate about  <code>where</code> clauses on enum variants? I'm not sure to follow</p>



<a name="152053674"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-12-17/near/152053674" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> scalexm <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-12-17.html#152053674">(Dec 17 2018 at 19:30)</a>:</h4>
<p>also I don't believe specialization needs a complete redesign, just stricter rules so that it is sound, which I believe <span class="user-mention" data-user-id="116009">@nikomatsakis</span> have worked on a bit already</p>



<a name="152053717"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-12-17/near/152053717" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-12-17.html#152053717">(Dec 17 2018 at 19:31)</a>:</h4>
<blockquote>
<p>also, <em>I suspect</em> finishing chalkification should make it easier to iterate on a lot of things we're talking about</p>
</blockquote>
<p>I believe this to be true, for sure</p>



<a name="152053726"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-12-17/near/152053726" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> centril <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-12-17.html#152053726">(Dec 17 2018 at 19:31)</a>:</h4>
<p><span class="user-mention" data-user-id="131694">@scalexm</span>  what I mean by "redesign" is a T-lang RFC to rework the accepted semantics; I'm interested in something along the lines Aaron set out</p>



<a name="152053739"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-12-17/near/152053739" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> centril <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-12-17.html#152053739">(Dec 17 2018 at 19:32)</a>:</h4>
<p>particularly the surface syntax</p>



<a name="152053788"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-12-17/near/152053788" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-12-17.html#152053788">(Dec 17 2018 at 19:32)</a>:</h4>
<p>I agree we need to write up a complete proposal with the new semantics</p>



<a name="152053803"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-12-17/near/152053803" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-12-17.html#152053803">(Dec 17 2018 at 19:32)</a>:</h4>
<p>I'm not sure exactly what process I think is most appropriate, but an RFC seems potentially OK</p>



<a name="152053805"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-12-17/near/152053805" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> scalexm <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-12-17.html#152053805">(Dec 17 2018 at 19:32)</a>:</h4>
<blockquote>
<p>yeah; <span class="user-mention" data-user-id="116883">@tmandry</span>  I'm working on an RFC for <code>for&lt;T: Foo + 'a&gt;</code> +/- generic closures; that would also benefit from chalk</p>
</blockquote>
<p>Indeed i believe this would be easier with chalk</p>



<a name="152053825"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-12-17/near/152053825" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-12-17.html#152053825">(Dec 17 2018 at 19:32)</a>:</h4>
<p>hmm that reminds me</p>



<a name="152053831"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-12-17/near/152053831" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> centril <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-12-17.html#152053831">(Dec 17 2018 at 19:32)</a>:</h4>
<p><span class="user-mention" data-user-id="131694">@scalexm</span> <code>enum Expr&lt;T&gt; { Plus(Box&lt;Expr&lt;T&gt;&gt;, Box&lt;Expr&lt;T&gt;&gt;) where T: Add, Minus(Box&lt;Expr&lt;T&gt;&gt;, Box&lt;Expr&lt;T&gt;&gt;) where T: Sub, ... }</code></p>



<a name="152053839"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-12-17/near/152053839" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> centril <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-12-17.html#152053839">(Dec 17 2018 at 19:33)</a>:</h4>
<p>GADTs without existentials, essentially</p>



<a name="152053845"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-12-17/near/152053845" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-12-17.html#152053845">(Dec 17 2018 at 19:33)</a>:</h4>
<p>there are some soundness holes (most notably <a href="https://github.com/rust-lang/rust/issues/25860" target="_blank" title="https://github.com/rust-lang/rust/issues/25860">#25860</a>) I've been expecting to close once chalk is in place</p>



<a name="152053846"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-12-17/near/152053846" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> scalexm <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-12-17.html#152053846">(Dec 17 2018 at 19:33)</a>:</h4>
<p>we may even ben able to model it in the chalk repo already</p>



<a name="152053943"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-12-17/near/152053943" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-12-17.html#152053943">(Dec 17 2018 at 19:34)</a>:</h4>
<p><span class="user-mention" data-user-id="126931">@centril</span> what is "ConstraintKinds"?</p>



<a name="152053959"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-12-17/near/152053959" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> centril <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-12-17.html#152053959">(Dec 17 2018 at 19:34)</a>:</h4>
<p><span class="user-mention" data-user-id="116009">@nikomatsakis</span> <a href="https://kseo.github.io/posts/2017-01-13-constraint-kinds.html" target="_blank" title="https://kseo.github.io/posts/2017-01-13-constraint-kinds.html">https://kseo.github.io/posts/2017-01-13-constraint-kinds.html</a></p>



<a name="152053971"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-12-17/near/152053971" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-12-17.html#152053971">(Dec 17 2018 at 19:34)</a>:</h4>
<p>(this whole discussion also gets at something I'm wanting us to thikn about, which is how to reshape the <strong>lang team</strong> so that it is operating in a more decentralized fashion)</p>



<a name="152054000"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-12-17/near/152054000" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> centril <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-12-17.html#152054000">(Dec 17 2018 at 19:35)</a>:</h4>
<p>i.e. <code>foo&lt;trait T&gt;</code> + associated traits</p>



<a name="152054030"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-12-17/near/152054030" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-12-17.html#152054030">(Dec 17 2018 at 19:35)</a>:</h4>
<p>I don't really know that that is supposed to mean</p>



<a name="152054040"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-12-17/near/152054040" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-12-17.html#152054040">(Dec 17 2018 at 19:35)</a>:</h4>
<p>I'm familiar with the term from haskell but kind of forgot the details</p>



<a name="152054119"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-12-17/near/152054119" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> centril <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-12-17.html#152054119">(Dec 17 2018 at 19:36)</a>:</h4>
<p><span class="user-mention" data-user-id="116009">@nikomatsakis</span>  it makes "trait" a kind that users can quantify; I haven't done any work on this in a while, but: <a href="https://github.com/Centril/rfc-trait-parametric-polymorphism/" target="_blank" title="https://github.com/Centril/rfc-trait-parametric-polymorphism/">https://github.com/Centril/rfc-trait-parametric-polymorphism/</a></p>



<a name="152054153"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-12-17/near/152054153" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-12-17.html#152054153">(Dec 17 2018 at 19:37)</a>:</h4>
<p>I see, ok.</p>



<a name="152054167"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-12-17/near/152054167" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-12-17.html#152054167">(Dec 17 2018 at 19:37)</a>:</h4>
<p>well, that all seems 100% blocked on chalk :)</p>



<a name="152054170"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-12-17/near/152054170" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> centril <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-12-17.html#152054170">(Dec 17 2018 at 19:37)</a>:</h4>
<p>(iirc we discussed this before and you likened it to something in prolog...)</p>



<a name="152054179"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-12-17/near/152054179" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-12-17.html#152054179">(Dec 17 2018 at 19:37)</a>:</h4>
<p>yes, I recall</p>



<a name="152054182"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-12-17/near/152054182" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> centril <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-12-17.html#152054182">(Dec 17 2018 at 19:37)</a>:</h4>
<p>yeah; 100% ;)</p>



<a name="152054265"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-12-17/near/152054265" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-12-17.html#152054265">(Dec 17 2018 at 19:38)</a>:</h4>
<p>(along these lines, I am thinking about the process for "ratifying" the lowering from traits to logic -- I don't know that an RFC is necessarily the right thing, but it feels like it is "cementing" part of Rust's semantics that have heretofore been unspecified, and it would be nic to make it "official" once we feel good about it)</p>



<a name="152054303"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-12-17/near/152054303" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-12-17.html#152054303">(Dec 17 2018 at 19:39)</a>:</h4>
<p>though I think there remain some interesting questions -- e.g., I continue to feel like there is probably a higher-level logic that could be used as an intermediate step</p>



<a name="152054322"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-12-17/near/152054322" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-12-17.html#152054322">(Dec 17 2018 at 19:39)</a>:</h4>
<p>anyway</p>



<a name="152054340"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-12-17/near/152054340" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> centril <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-12-17.html#152054340">(Dec 17 2018 at 19:39)</a>:</h4>
<p>(depends on how detailed you want to be; a formal specification for traits/operational-semantics/other-stuff in Agda/Coq/Lean/F*/insert-random-theorem-prover would be nice for high-detail stuff)</p>



<a name="152054482"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-12-17/near/152054482" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> tmandry <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-12-17.html#152054482">(Dec 17 2018 at 19:41)</a>:</h4>
<p>So, chalkification:<br>
- unblocks oft-requested features<br>
- unblocks or speeds up experimentation on new ones<br>
- pays down technical debt<br>
- potentially speeds up compiler a lot<br>
it's pretty clear to me this should be a priority :)</p>



<a name="152054512"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-12-17/near/152054512" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-12-17.html#152054512">(Dec 17 2018 at 19:41)</a>:</h4>
<p>I'm curious whether people see things as missing from <a href="https://hackmd.io/i32CFrbQSsmDZ0vBheggWg" target="_blank" title="https://hackmd.io/i32CFrbQSsmDZ0vBheggWg">this list</a></p>



<a name="152054562"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-12-17/near/152054562" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-12-17.html#152054562">(Dec 17 2018 at 19:42)</a>:</h4>
<p><span class="user-mention" data-user-id="124069">@Alexander Regueiro</span> in particular I would like you to take a look <span class="emoji emoji-1f446" title="point up">:point_up:</span></p>



<a name="152054594"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-12-17/near/152054594" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> tmandry <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-12-17.html#152054594">(Dec 17 2018 at 19:42)</a>:</h4>
<p>perhaps a preemptible one, for shipping larger rust-wide pushes such as async.. I personally can see the value in getting that really polished</p>



<a name="152054636"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-12-17/near/152054636" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> centril <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-12-17.html#152054636">(Dec 17 2018 at 19:43)</a>:</h4>
<p><span class="user-mention" data-user-id="116009">@nikomatsakis</span>  I thought <code>type Foo = impl Trait;</code> wasn't blocked on chalk?</p>



<a name="152054659"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-12-17/near/152054659" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-12-17.html#152054659">(Dec 17 2018 at 19:43)</a>:</h4>
<p>yeah, probably. I am still feeling pretty good about pushing harder on chalk for time being, but I'd like to feel like we have a kind of roadmap of how to proceed, and make sure we're not just rushing in</p>



<a name="152054680"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-12-17/near/152054680" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-12-17.html#152054680">(Dec 17 2018 at 19:43)</a>:</h4>
<blockquote>
<p>I thought <code>type Foo = impl Trait;</code> wasn't blocked on chalk?</p>
</blockquote>
<p>did I say otherwise?</p>



<a name="152054709"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-12-17/near/152054709" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-12-17.html#152054709">(Dec 17 2018 at 19:44)</a>:</h4>
<p>I do think there is some work <em>in chalk</em> probably needed here, since impl Trait isn't really suported or modeled by chalk right now</p>



<a name="152054743"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-12-17/near/152054743" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> tmandry <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-12-17.html#152054743">(Dec 17 2018 at 19:44)</a>:</h4>
<p><em>nods</em></p>



<a name="152054744"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-12-17/near/152054744" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-12-17.html#152054744">(Dec 17 2018 at 19:44)</a>:</h4>
<p>this is not a list of "things blocked on chalk"</p>



<a name="152054747"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-12-17/near/152054747" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-12-17.html#152054747">(Dec 17 2018 at 19:44)</a>:</h4>
<p>it's a list of "things we want to do"</p>



<a name="152054748"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-12-17/near/152054748" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> centril <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-12-17.html#152054748">(Dec 17 2018 at 19:44)</a>:</h4>
<p><span class="user-mention" data-user-id="116009">@nikomatsakis</span>  I assumed "trait system area" meant chalk :P</p>



<a name="152054751"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-12-17/near/152054751" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> centril <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-12-17.html#152054751">(Dec 17 2018 at 19:44)</a>:</h4>
<p>oh :P</p>



<a name="152054755"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-12-17/near/152054755" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> centril <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-12-17.html#152054755">(Dec 17 2018 at 19:44)</a>:</h4>
<p>yeah it makes more sense now</p>



<a name="152054931"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-12-17/near/152054931" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-12-17.html#152054931">(Dec 17 2018 at 19:46)</a>:</h4>
<p>ok, well, before we go, a question of scheduling:</p>



<a name="152054933"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-12-17/near/152054933" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-12-17.html#152054933">(Dec 17 2018 at 19:46)</a>:</h4>
<p>the next meeting is Dec 24</p>



<a name="152054937"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-12-17/near/152054937" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-12-17.html#152054937">(Dec 17 2018 at 19:46)</a>:</h4>
<p>let's cancel that right now :)</p>



<a name="152054942"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-12-17/near/152054942" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-12-17.html#152054942">(Dec 17 2018 at 19:46)</a>:</h4>
<p>the meeting after that is Dec 31</p>



<a name="152054949"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-12-17/near/152054949" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-12-17.html#152054949">(Dec 17 2018 at 19:46)</a>:</h4>
<p>I'm thinking maybe cancel that too, and reconvene in Jan?</p>



<a name="152054956"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-12-17/near/152054956" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-12-17.html#152054956">(Dec 17 2018 at 19:46)</a>:</h4>
<p>I may or may not be working, I don't know</p>



<a name="152055001"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-12-17/near/152055001" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> tmandry <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-12-17.html#152055001">(Dec 17 2018 at 19:47)</a>:</h4>
<p>makes sense I think</p>



<a name="152055004"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-12-17/near/152055004" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> tmandry <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-12-17.html#152055004">(Dec 17 2018 at 19:47)</a>:</h4>
<p>we can sync up here on work as needed</p>



<a name="152055013"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-12-17/near/152055013" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-12-17.html#152055013">(Dec 17 2018 at 19:47)</a>:</h4>
<p>yeah that's what i'm thinking</p>



<a name="152055071"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-12-17/near/152055071" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> tmandry <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-12-17.html#152055071">(Dec 17 2018 at 19:48)</a>:</h4>
<p>going to try to get some guide work done this week</p>



<a name="152055124"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-12-17/near/152055124" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-12-17.html#152055124">(Dec 17 2018 at 19:49)</a>:</h4>
<p>cool</p>



<a name="152055129"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-12-17/near/152055129" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> tmandry <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-12-17.html#152055129">(Dec 17 2018 at 19:49)</a>:</h4>
<p>this doc is a good example of what a traits-wg repo would look like, I guess</p>



<a name="152055131"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-12-17/near/152055131" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> tmandry <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-12-17.html#152055131">(Dec 17 2018 at 19:49)</a>:</h4>
<p>?</p>



<a name="152055137"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-12-17/near/152055137" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> tmandry <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-12-17.html#152055137">(Dec 17 2018 at 19:49)</a>:</h4>
<p>each bullet point is an issue</p>



<a name="152055146"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-12-17/near/152055146" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-12-17.html#152055146">(Dec 17 2018 at 19:49)</a>:</h4>
<p>I imagine it would have a kind of "master roadmap" sort of like that</p>



<a name="152055155"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-12-17/near/152055155" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-12-17.html#152055155">(Dec 17 2018 at 19:49)</a>:</h4>
<p>plus in-progress rfcs</p>



<a name="152055160"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-12-17/near/152055160" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-12-17.html#152055160">(Dec 17 2018 at 19:49)</a>:</h4>
<p>where appropriate</p>



<a name="152055217"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-12-17/near/152055217" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-12-17.html#152055217">(Dec 17 2018 at 19:50)</a>:</h4>
<p>maybe using issues, maybe not</p>



<a name="152055244"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-12-17/near/152055244" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-12-17.html#152055244">(Dec 17 2018 at 19:51)</a>:</h4>
<p>I'm not sure it's a good place what's the best way to manage <em>discussion</em>, but I feel like collecting things together might be useful</p>



<a name="152055254"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-12-17/near/152055254" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-12-17.html#152055254">(Dec 17 2018 at 19:51)</a>:</h4>
<p>still trying to figure it out to be honest</p>



<a name="152055257"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-12-17/near/152055257" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> centril <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-12-17.html#152055257">(Dec 17 2018 at 19:51)</a>:</h4>
<p><span class="user-mention" data-user-id="116009">@nikomatsakis</span> added some notes to the hackmd doc</p>



<a name="152055327"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-12-17/near/152055327" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-12-17.html#152055327">(Dec 17 2018 at 19:52)</a>:</h4>
<p>I saw, thanks!</p>



<a name="152055347"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-12-17/near/152055347" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-12-17.html#152055347">(Dec 17 2018 at 19:52)</a>:</h4>
<p>ok, let's reconvene Jan 7 then</p>



<a name="152055354"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-12-17/near/152055354" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> tmandry <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-12-17.html#152055354">(Dec 17 2018 at 19:52)</a>:</h4>
<p>I think issues are better at getting updated than docs.. would be interesting to try putting "higher level tracking issues" here..?</p>



<a name="152055392"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-12-17/near/152055392" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> tmandry <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-12-17.html#152055392">(Dec 17 2018 at 19:52)</a>:</h4>
<p>oops just saw the rest of this</p>



<a name="152055420"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-12-17/near/152055420" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> centril <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-12-17.html#152055420">(Dec 17 2018 at 19:53)</a>:</h4>
<p>I'll see if I can start working on some non-trait related work in the compiler to learn my way to traits eventually :P</p>



<a name="152055432"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-12-17/near/152055432" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> centril <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-12-17.html#152055432">(Dec 17 2018 at 19:53)</a>:</h4>
<p>so I can implement my own RFCs, lol =P</p>



<a name="152055749"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-12-17/near/152055749" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> centril <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-12-17.html#152055749">(Dec 17 2018 at 19:57)</a>:</h4>
<p>(added some more notes again)</p>



<a name="152057143"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-12-17/near/152057143" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Alexander Regueiro <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-12-17.html#152057143">(Dec 17 2018 at 20:18)</a>:</h4>
<blockquote>
<blockquote>
<p><span class="user-mention" data-user-id="116009">@nikomatsakis</span> would appreciate some advice on what to do about that future compat warning for my trait aliases PR btw... I think that should become a regular lint, but we should leave a future compat warning in place for the coherence case? I'm not sure how to do it for coherence though, sounds kind of difficult.</p>
</blockquote>
<p>ok ye I can do that today</p>
</blockquote>
<p>thanks :-)</p>



<a name="152057177"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-12-17/near/152057177" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Alexander Regueiro <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-12-17.html#152057177">(Dec 17 2018 at 20:19)</a>:</h4>
<p><span class="user-mention" data-user-id="126931">@centril</span> yeah. wait until Chalk integration has completed anyway, since if you started now, you'd be relearning a lot.</p>



<a name="152057526"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-12-17/near/152057526" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Alexander Regueiro <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-12-17.html#152057526">(Dec 17 2018 at 20:24)</a>:</h4>
<p><span class="user-mention" data-user-id="116009">@nikomatsakis</span> okay, I looked at the document... 1) the trait objects point (upcasting &amp; multi-trait) should probably move to the second section, since there's no RFC yet. though it's possible dhardy or I will try an experimental implementation before/while the RFC is being written. 2) <code>for&lt;T: Debug&gt;</code> -- this is HRTB yes? probably worth saying so.</p>



<a name="152057527"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-12-17/near/152057527" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Alexander Regueiro <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-12-17.html#152057527">(Dec 17 2018 at 20:24)</a>:</h4>
<p>I can't edit unfortunately.</p>



<a name="152057593"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-12-17/near/152057593" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-12-17.html#152057593">(Dec 17 2018 at 20:25)</a>:</h4>
<p>I'm not that worried about whether an RFC exists, so much as the amount of "end-user design" that seems like it may be needed</p>



<a name="152057595"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-12-17/near/152057595" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Alexander Regueiro <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-12-17.html#152057595">(Dec 17 2018 at 20:25)</a>:</h4>
<p>err... yes, I can. turns out I just don't know how to use HackMD</p>



<a name="152057607"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-12-17/near/152057607" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-12-17.html#152057607">(Dec 17 2018 at 20:25)</a>:</h4>
<p>(but feel free to move around)</p>



<a name="152057731"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/144729-wg-traits/topic/weekly%20meeting%202018-12-17/near/152057731" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Alexander Regueiro <a href="https://rust-lang.github.io/zulip_archive/stream/144729-wg-traits/topic/weekly.20meeting.202018-12-17.html#152057731">(Dec 17 2018 at 20:27)</a>:</h4>
<p>anyway, list looks good</p>



<hr><p>Last updated: Aug 07 2021 at 22:04 UTC</p>
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